<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Log
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Log.php 18951 2009-11-12 16:26:19Z alexander $
 */

/**
 * @category   Zend
 * @package    Zend_Log
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Log.php 18951 2009-11-12 16:26:19Z alexander $
 */
class Zend_Log
{
	const EMERG   = 0;  // Emergency: system is unusable
	const ALERT   = 1;  // Alert: action must be taken immediately
	const CRIT    = 2;  // Critical: critical conditions
	const ERR     = 3;  // Error: error conditions
	const WARN    = 4;  // Warning: warning conditions
	const NOTICE  = 5;  // Notice: normal but significant condition
	const INFO    = 6;  // Informational: informational messages
	const DEBUG   = 7;  // Debug: debug messages

	/**
	 * @var array of priorities where the keys are the
	 * priority numbers and the values are the priority names
	 */
	protected $_priorities = array();

	/**
	 * @var array of Zend_Log_Writer_Abstract
	 */
	protected $_writers = array();

	/**
	 * @var array of Zend_Log_Filter_Interface
	 */
	protected $_filters = array();

	/**
	 * @var array of extra log event
	 */
	protected $_extras = array();

	/**
	 * Class constructor.  Create a new logger
	 *
	 * @param Zend_Log_Writer_Abstract|null  $writer  default writer
	 */
	public function __construct(Zend_Log_Writer_Abstract $writer = null)
	{
		$r = new ReflectionClass($this);
		$this->_priorities = array_flip($r->getConstants());

		if ($writer !== null) {
			$this->addWriter($writer);
		}
	}

	/**
	 * Class destructor.  Shutdown log writers
	 *
	 * @return void
	 */
	public function __destruct()
	{
		foreach($this->_writers as $writer) {
			$writer->shutdown();
		}
	}

	/**
	 * Undefined method handler allows a shortcut:
	 *   $log->priorityName('message')
	 *     instead of
	 *   $log->log('message', Zend_Log::PRIORITY_NAME)
	 *
	 * @param  string  $method  priority name
	 * @param  string  $params  message to log
	 * @return void
	 * @throws Zend_Log_Exception
	 */
	public function __call($method, $params)
	{
		$priority = strtoupper($method);
		if (($priority = array_search($priority, $this->_priorities)) !== false) {
			$this->log(array_shift($params), $priority);
		} else {
			/** @see Zend_Log_Exception */
			require_once 'Zend/Log/Exception.php';
			throw new Zend_Log_Exception('Bad log priority');
		}
	}

	/**
	 * Log a message at a priority
	 *
	 * @param  string   $message   Message to log
	 * @param  integer  $priority  Priority of message
	 * @return void
	 * @throws Zend_Log_Exception
	 */
	public function log($message, $priority)
	{
		// sanity checks
		if (empty($this->_writers)) {
			/** @see Zend_Log_Exception */
			require_once 'Zend/Log/Exception.php';
			throw new Zend_Log_Exception('No writers were added');
		}

		if (! isset($this->_priorities[$priority])) {
			/** @see Zend_Log_Exception */
			require_once 'Zend/Log/Exception.php';
			throw new Zend_Log_Exception('Bad log priority');
		}

		// pack into event required by filters and writers
		$event = array_merge(array('timestamp'    => date('c'),
                                    'message'      => $message,
                                    'priority'     => $priority,
                                    'priorityName' => $this->_priorities[$priority]),
		$this->_extras);

		// abort if rejected by the global filters
		foreach ($this->_filters as $filter) {
			if (! $filter->accept($event)) {
				return;
			}
		}

		// send to each writer
		foreach ($this->_writers as $writer) {
			$writer->write($event);
		}
	}

	/**
	 * Add a custom priority
	 *
	 * @param  string   $name      Name of priority
	 * @param  integer  $priority  Numeric priority
	 * @throws Zend_Log_InvalidArgumentException
	 */
	public function addPriority($name, $priority)
	{
		// Priority names must be uppercase for predictability.
		$name = strtoupper($name);

		if (isset($this->_priorities[$priority])
		|| array_search($name, $this->_priorities)) {
			/** @see Zend_Log_Exception */
			require_once 'Zend/Log/Exception.php';
			throw new Zend_Log_Exception('Existing priorities cannot be overwritten');
		}

		$this->_priorities[$priority] = $name;
	}

	/**
	 * Add a filter that will be applied before all log writers.
	 * Before a message will be received by any of the writers, it
	 * must be accepted by all filters added with this method.
	 *
	 * @param  int|Zend_Log_Filter_Interface $filter
	 * @return void
	 */
	public function addFilter($filter)
	{
		if (is_integer($filter)) {
			/** @see Zend_Log_Filter_Priority */
			require_once 'Zend/Log/Filter/Priority.php';
			$filter = new Zend_Log_Filter_Priority($filter);
		} elseif(!is_object($filter) || ! $filter instanceof Zend_Log_Filter_Interface) {
			/** @see Zend_Log_Exception */
			require_once 'Zend/Log/Exception.php';
			throw new Zend_Log_Exception('Invalid filter provided');
		}

		$this->_filters[] = $filter;
	}

	/**
	 * Add a writer.  A writer is responsible for taking a log
	 * message and writing it out to storage.
	 *
	 * @param  Zend_Log_Writer_Abstract $writer
	 * @return void
	 */
	public function addWriter(Zend_Log_Writer_Abstract $writer)
	{
		$this->_writers[] = $writer;
	}

	/**
	 * Set an extra item to pass to the log writers.
	 *
	 * @param  $name    Name of the field
	 * @param  $value   Value of the field
	 * @return void
	 */
	public function setEventItem($name, $value) {
		$this->_extras = array_merge($this->_extras, array($name => $value));
	}

}
